[PATCH mm-unstable v2 1/9] mm/shmem: add flag to enforce shmem THP in hugepage_vma_check()
From: Zach O'Keefe <hidden>
Date: 2022-08-26 22:03:38
Also in:
linux-mm
Subsystem:
memory management, memory management - thp (transparent huge page), the rest, tmpfs (shmem filesystem) · Maintainers:
Andrew Morton, David Hildenbrand, Lorenzo Stoakes, Linus Torvalds, Hugh Dickins
Extend 'mm/thp: add flag to enforce sysfs THP in hugepage_vma_check()' to shmem, allowing callers to ignore /sys/kernel/transparent_hugepage/shmem_enabled and tmpfs huge= mount. This is intended to be used by MADV_COLLAPSE, and the rationale is analogous to the anon/file case: MADV_COLLAPSE is not coupled to directives that advise the kernel's decisions on when THPs should be considered eligible. shmem/tmpfs always claims large folio support, regardless of sysfs or mount options. Signed-off-by: Zach O'Keefe <redacted> --- include/linux/shmem_fs.h | 10 ++++++---- mm/huge_memory.c | 2 +- mm/shmem.c | 18 +++++++++--------- 3 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index ff0b990de83d..f5e9b01dbf4c 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h@@ -92,11 +92,13 @@ extern struct page *shmem_read_mapping_page_gfp(struct address_space *mapping, extern void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end); int shmem_unuse(unsigned int type); -extern bool shmem_is_huge(struct vm_area_struct *vma, - struct inode *inode, pgoff_t index); -static inline bool shmem_huge_enabled(struct vm_area_struct *vma) +extern bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode, + pgoff_t index, bool shmem_huge_force); +static inline bool shmem_huge_enabled(struct vm_area_struct *vma, + bool shmem_huge_force) { - return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff); + return shmem_is_huge(vma, file_inode(vma->vm_file), vma->vm_pgoff, + shmem_huge_force); } extern unsigned long shmem_swap_usage(struct vm_area_struct *vma); extern unsigned long shmem_partial_swap_usage(struct address_space *mapping,
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 88d98241a635..b3acc8e3046d 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c@@ -119,7 +119,7 @@ bool hugepage_vma_check(struct vm_area_struct *vma, unsigned long vm_flags, * own flags. */ if (!in_pf && shmem_file(vma->vm_file)) - return shmem_huge_enabled(vma); + return shmem_huge_enabled(vma, !enforce_sysfs); /* Enforce sysfs THP requirements as necessary */ if (enforce_sysfs &&
diff --git a/mm/shmem.c b/mm/shmem.c
index 42e5888bf84d..b9bab1abf142 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c@@ -472,20 +472,20 @@ static bool shmem_confirm_swap(struct address_space *mapping, static int shmem_huge __read_mostly = SHMEM_HUGE_NEVER; -bool shmem_is_huge(struct vm_area_struct *vma, - struct inode *inode, pgoff_t index) +bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode, + pgoff_t index, bool shmem_huge_force) { loff_t i_size; if (!S_ISREG(inode->i_mode)) return false; - if (shmem_huge == SHMEM_HUGE_DENY) - return false; if (vma && ((vma->vm_flags & VM_NOHUGEPAGE) || test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags))) return false; - if (shmem_huge == SHMEM_HUGE_FORCE) + if (shmem_huge == SHMEM_HUGE_FORCE || shmem_huge_force) return true; + if (shmem_huge == SHMEM_HUGE_DENY) + return false; switch (SHMEM_SB(inode->i_sb)->huge) { case SHMEM_HUGE_ALWAYS:
@@ -680,8 +680,8 @@ static long shmem_unused_huge_count(struct super_block *sb, #define shmem_huge SHMEM_HUGE_DENY -bool shmem_is_huge(struct vm_area_struct *vma, - struct inode *inode, pgoff_t index) +bool shmem_is_huge(struct vm_area_struct *vma, struct inode *inode, + pgoff_t index, bool shmem_huge_force) { return false; }
@@ -1069,7 +1069,7 @@ static int shmem_getattr(struct user_namespace *mnt_userns, STATX_ATTR_NODUMP); generic_fillattr(&init_user_ns, inode, stat); - if (shmem_is_huge(NULL, inode, 0)) + if (shmem_is_huge(NULL, inode, 0, false)) stat->blksize = HPAGE_PMD_SIZE; if (request_mask & STATX_BTIME) {
@@ -1910,7 +1910,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, return 0; } - if (!shmem_is_huge(vma, inode, index)) + if (!shmem_is_huge(vma, inode, index, false)) goto alloc_nohuge; huge_gfp = vma_thp_gfp_mask(vma);
--
2.37.2.672.g94769d06f0-goog